1. Field of the Invention
The present invention relates generally to digital broadcasting, and in particular, to a method and system for displaying digital broadcast signals on an external device that is linked to a portable terminal including a digital broadcast receiver.
2. Description of the Related Art
Portable terminals are intended to install a multimedia-dedicated processor to enhance multimedia functions. Portable terminals install a digital broadcast receiver to enhance multimedia functions. To provide numerous multimedia functions, portable terminals must be configured to include a plurality of parts, which increases complexity of their configurations and makes their control harder.
Conventional portable terminals have a restriction in the size of a display unit for displaying multimedia data and in the playback ability of the speaker. Since the conventional portable terminals, such as a mobile phone, etc., are relatively small, the screen size of the display unit for displaying the received broadcast signal and the sound performance must be necessarily restricted. To resolve such a restriction, the portable terminals add a function to associate with an external device that their outputs can be played back through the external device. In that case, the portable terminals demodulate received broadcast signals; separate video and audio signals from the demodulated broadcast signals to decode them, respectively; and convert the decoded video and audio signals into the video and audio signals to output the converted signals to the external device.
However, the conventional broadcast signal process increases the amount of audio and video signals that the portable terminal will transmit. The portable terminal must transmit decoded broadcast signals to the external device. But the decoded broadcast signals include a large amount of information much greater than that of compressed broadcast signals. In particular, when the broadcast signals are digital broadcast signals, it is difficult for the portable terminal to transmit video data to the external device at 25 frames per second.
Also, the conventional broadcast signal process is disadvantageous in that the external device is only able to play back the broadcast signals transmitted from the portable terminal but not to control the broadcast signals. Although the conventional portable terminal is configured to be equipped with a communication function and thus provides incoming and outgoing call functions, it cannot process an incoming call signal received while the external device is playing broadcast signals back. Also, the conventional portable terminal cannot process an outgoing call signal while the external device is playing broadcast signals back.